Brie Larson burst onto the scene this year with Destin Cretton’s indie film “Short Term 12,” winning Gotham and Detroit Film Critics Awards for her breakthrough performance as Grace, a supervisor at a foster-care facility who battles her own troubled past.

But Larson, 24, has been acting since the age of seven, and her other films this year, “The Spectacular Now” and “Don Jon,” have also made waves — helping to cement the young actress’s standing in Hollywood.

“All three of them happened back-to-back at the end of the year and it was a really fun way to work,” Larson said, “for me to be a frequently working, not a full-time actor. They were all completely different experiences.”

“Short Term 12″ will be released Tuesday on Blu-ray/DVD. L.A.-based Larson, who is also nominated for Independent Spirit and Critics Choice Awards, talked with Speakeasy about building her “Short Term 12″ character Grace, doing the film’s explosive scenes, and dealing with all the new attention during awards season.

How did you build this character, Grace, as a leader in this foster-care facility and also as a young woman with her own rage?

Brie Larson at the Gotham Independent Film Awards in New York in December 2013.

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It was a combination of things because she’s quite contradictory and complicated, as humans are. It started with learning about the foster-care facility and understanding the rules of the game — how does it work, what are the hours like, what are the financial requirements, how does that restrict their rights, and the pressures that come out of that. Then learning about how you would individually cater to each child. I had my own style with each one of the kids in the film because I felt like she would have different expectations and different ways of speaking to different kids because you would know what triggers they would have, or what kind of physical contact they’re willing to have with you. The rest of it is more for myself. I just create my own path to Grace and really work on my own internal world for her in particular because she’s constantly thinking about something else. I wanted to know how she was thinking about them, and how dark those thoughts would get.

How was it working with those kids? It’s hard to believe they’re actors.

The kids are incredible because they are actors and they were on set with their extremely devoted and loving parents every day. It was incredible to watch just pure talent that was coming out of these kids. They haven’t experienced the pain and the abandonment that these kids they’re portraying have, but they understood it and knew how to feel it themselves. It was still within them. It was amazing to watch.

The head-shaving scene with Marcus was so unexpected and startling. Did you film that scene a few times?

We were a super low-budget movie so we did not have the luxury of a lot of takes. Most days we kind of got it on the first take and then we’d try it a couple more times, and then move on. It was kind of all we had time for. But Keith [Stanfield, who plays Marcus] was completely engrossed in his character and kind of went a little Method. It was his first film, he had only done the short film, “Short Term 12,” and he just kind of removed himself from the set. He felt like his character didn’t talk to anybody or was completely alone, and he wanted to feel that way. He wouldn’t sit with us at lunch. He told me upfront that he wasn’t going to talk to me, and he didn’t. So it made scenes like the head-shaving scene that much more heartbreaking for us, because I didn’t know who this person was. He would not reveal himself to me, even when the cameras weren’t rolling. It’s been through the process of actually traveling and promoting the film that I’ve gotten to know Keith and he’s such a remarkable person.

In terms of channeling Grace’s other emotions, what was that journey like for you as an actress?

Because we were working with a small crew and I became so close to the gaffer and the DP, I didn’t want to feel self-conscious about having to become this side of Grace that isn’t the most beautiful side, and it isn’t the most giving and caring — it’s actually the more selfish parts inside of her that are struggling inside. I just told everyone on set hey, I’m going to go underwater for a little bit and I’ll let you know when I come out. I listened to a lot of black metal, that helped me believe that I was in a certain place. You do a couple takes and then Destin [Cretton, the director] gives you a hug, and that’s when you laugh about how crazy you look.

Was there anything external that also helped you build this performance?

No, it was very internal. I don’t think I’ve ever seen a movie or any sort of representation that I would consider to be Grace other than Grace — and perhaps some of the women I shadowed at the foster care facilities. But it’s a strange thing because I read the script and I just knew who she was and I knew how to do it. And then I did it the way that I thought it should be done. It’s very interesting now to look back on it and say oh, it’s amazing how the creative process works and you feel certain of something. I don’t know why I knew her, but I knew her.

Has this film struck a more personal nerve with you in terms of how people are responding to it?

It’s been an incredible journey with this film because it’s such a small independent, it’s fighting for survival everyday, much like the characters you see in the movie. The whole movie was such a loving experience, such a loving set with this incredible group of people. I feel like the movie is this strange little package of love that gets sent around the world. People receive it and they feel for these characters, and they feel for themselves and the whole world. It gets me excited because I believe in the power of film. I believe in the synesthetic experience of it and it’s exciting to see that even the smallest of movies can still create an impact.

How are you navigating awards season?

It’s a bit different. I don’t know. I don’t think I really understand it very well. The Gotham Awards were really exciting. I was very nervous about it because I never accepted an award before and I didn’t know if I knew how to do it. I have a hard time when the attention is specifically on me because I don’t believe that it’s about me. I don’t believe the movie is about me. Grace isn’t me, she was still written by Destin. It’s still strange. I feel like I’m part of something that’s magical. It’s not just me that’s the magic. So I’ve had difficulty in accepting that. But I got to have this incredible realization as I was walking up to receive the Gotham Award. I realized it was a symbol and an opportunity for me to publicly express my love and gratitude to so many people who have been extremely generous with their time and words and have loved me through an extremely difficult, long process, and have helped me when I needed help. That felt so gratifying and in my mind, I don’t need to win anything else because I was given the exact opportunity that i needed, which was to give a thank you from the bottom of my heart.

Do you mean specifically for this film, or in general?

No, in general. I’ve been an actor since I was seven years old. My mom changed her life in order to accommodate my dream. It took a really long time but it paid off and I wanted to say my appreciation to my family and to my representation, who are also like my family, for putting so much time into this dream.

About Speakeasy

Speakeasy is a blog covering media, entertainment, celebrity and the arts. The publication is produced by Barbara Chai and Jonathan Welsh with contributions from the Wall Street Journal staff and others. Write to us at speakeasy@wsj.com or follow us on Twitter at @WSJSpeakeasy or individually @barbarachai.